1. Field of the Invention
This invention relates to systems for controlling the aim of a gun which is remote from the gunner.
2. Prior Art
The conventional fire control systems used on turrets in aircraft, for example, attack helicopters, depend on the gunner's estimate of the slant range. When 20 and 30mm guns, with their longer range capability, are installed on such aircraft, estimation of range becomes inadequate for two reasons. First, the gunner has all he can do to properly aim the sight during the rapidly changing dynamic situations caused by aircraft maneuvers and wind disturbances, so that the added task of mentally making a judgment as to the instantaneous slant range detracts from his tracking capability. Second, it has been shown that a gunner's ability to estimate range can easily be in error by as much as 40% and generally is about 25%. At ranges in excess of 1000 meters, such a range error produces a ballistic drop error large enough to noticeably reduce the effectiveness of the weapon system.
Conventional attempts to solve the range determination problem have used an optical stadiametric or stereoptic ranging device located on the gunner's sight, which is cumbersome for the gunner to use and inherently imprecise. Laser range finders have been used in some developmental helicopter fire control systems, mounted on an independentally gimbaled platform, and are bulky, expensive and complex.